Integrated circuits (ICs) may utilize a range of supply voltages and/or currents. Within each voltage domain, logical states 0 and 1 may be defined by upper and lower limits of corresponding operating voltages or voltage swings.
Where data is passed from a first voltage domain to a second voltage domain, the data may be translated from a voltage swing of the first voltage domain to a voltage swing of the second voltage domain to permit appropriate switching of logic levels and to avoid communication static in the second voltage domain.
Translation may be performed with a voltage level shift circuit, which may include cascode voltage switch logic (CVSL), and which may include differential cascode voltage switch logic (DCVSL).
Contention is inherent in a CVSL or DCVSL based voltage level shifter. Contention may increase when increasing differences between input and output voltages. Greater contention may increase delay and power consumption, and may impact operating function.
A voltage level shifter may include a contention interrupt circuit to control contention based on an input logical state. Where the input and output voltages differ significantly, process-based voltage reliability limits of the contention interrupt circuit may be exceeded. Tolerance to input and output voltage differences may be increased with increased interrupt transistor sizes, but at the potential expense of power consumption, and area consumption, and/or delay.
In the drawings, the leftmost digit(s) of a reference number identifies the drawing in which the reference number first appears.